Moduł ten eliminuje niektóre artefakty pasm, które mogą wystąpić, gdy wewnętrzne 32-bitowe dane zmiennoprzecinkowe Ansel są przesyłane do dyskretnego 8-bitowego lub 16-bitowego całkowitego formatu wyjściowego w celu wyświetlenia lub eksportu.
Although not an inherent problem in any of Ansel’s modules, some operations may provoke banding if they produce a lightness gradient in the image. To mitigate possible artifacts you should consider activating dithering when using the vignetting or graduated density modules. This is especially relevant for images with extended homogeneous areas such as cloudless sky. Also watch out for banding artifacts when using a gradient drawn mask.
Viewing an image dithered into a very low bit depth from some distance (e.g. “Floyd-Steinberg 1-bit b&w”) will give the impression of a homogeneous grayscale image. Ansel attempts to mimic this impression when rendering zoomed-out images in the center view, the navigation window and thumbnails. This is accomplished by dithering those images into a higher number of grayscale levels. Note that, as a consequence, the scopes module – the data for which is derived from the navigation window – will show this increased number of levels and is therefore not a full match to the output image.
kontrolki modułu
- method
- Choose the dithering method to use.
Floyd-Steinberg: Systematically distribute quantization errors over neighboring pixels. This method can be selected with some typical output bit depths. Alternatively, you can select Floyd-Steinberg auto, which automatically adapts to the desired output format.
random dithering: This method just adds some level of randomness to break sharp tonal value bands.
- tłumienie (tylko metoda „losowa”)
- Kontroluje poziom dodanego losowego szumu wyrażony jako współczynnik tłumienia na podstawie 10*log 2. Wartość -80 dobrze pasuje do 8-bitowych formatów wyjściowych; -160 dla wyjścia 16-bitowego.